Search Results

Vehicles which are sold and put into service in a country have to meet the regulations and standards of that country. Every country has a separate regulation and approval procedure which requires expensive design modifications, additional tests and duplicating approvals. Thus, there is the need to harmonize the different national technical requirements for vehicles and form a unique international regulation. With this rationale, the World Forum for Harmonization of Vehicle Regulations of the United Nations Economic Commission for Europe (UN/ECE/WP29) has brought governments and automobile manufacturers together to work on a new harmonized test cycle and procedure which is to be adopted around the world. This lead to the development of Worldwide Harmonized Light Duty Test Procedures (WLTP) and Cycles (WLTC). The test procedure is divided into 3 cycles, depending on a power to mass ratio of the tested vehicle.

Valve train system is one major contributor to engine overall friction loss and is approximately 30% of total engine friction at lower speed and approximately 20 % at higher engine speed. Valve spring loads (preload and working) are proportional to friction loss of valve train. To optimizing the valve spring design main requirement is valve train perform it function safely at maximum engine cutoff RPM with minimum preload and working load. Robustness and frictional power loss are contradicting requirement, robustness demand high stiffness spring for better valve jump and bounce performance with dynamic safe valve spring design, on the other hand low frictional power loss demand for use of low stiffness spring. To optimize the valve spring stiffness for meeting both the requirement we need accurate prediction of valve spring in design stage and good correlation with testing data to reduce the number of iterations.

Fun to drive, pick-up of vehicle, high acceleration feeling of vehicle, time to reach max velocities are some parameters prevailing in the passenger vehicle market. In addition to focusing on information about fuel economy declared by manufacturer, the customer also has drivability related criteria in his mind. Although drivability is subjective, it can be judged by using various parameters like maximum speed, pick-up feeling, overtaking acceleration, time to reach 0 – 100 km/h or 0 – 60 km/h, etc. While comparing two vehicles of the same segment, one vehicle may perform better on some of the parameters while losses on others. To decide overall drive performance of a vehicle based on various measured performance related parameters, a methodology is defined. This will help to understand the overall performance of a vehicle holistically and to compare its performance with other vehicles in a better way.

Automobile components are usually subjected to complex varying loads. Thus, fatigue failure is a common mode of failure in automobile components. Accurately predicting the fatigue life is the key point for light weight and also reliability design of automobile components. Various life prediction theories are being used in the automotive industry for damage analysis using material S-N curves. However, due to variability in manufacturing, material spec etc. it is difficult to predict the experimental lives using conventional theories. Probability based statistical modeling is prevalent in the industry for life prediction. Probabilistic plots of cycles to failure to constant amplitude loads are plotted and used for prediction purpose. As the component is subjected to varying loads in real world, defining a single parameter i.e. damage would be more relevant compared to loads.

India is a country of diversity. From North to South, east to west, one can find altogether different culture, religions, spoken languages, foods, weather conditions, people lifestyles, dressing styles etc. This vast diversity of India poses a great challenge in front of Indian Automobile Manufacturers, so as to assimilate all the requirements (of this big nation) in one single car (design). For example, many people in India wear turban (out of their religious beliefs or cultural heritage). So, is it required to keep enough consideration for Turban wearing population in vehicle design? Turban, unlike caps or hats, is something which is tied on the head (not just only kept). It is something which cannot be removed whenever required. So, it can somehow be considered as an integral part of body (as an added head dimension). So, it becomes all the more important to thoroughly understand this aspect & keep a consideration for the same in vehicle design.

Hybrid Electric Vehicle (HEV) Controls Development is an important aspect to realize the goals of Powertrain Electrification i.e. fuel economy and emission improvement. Keeping that in mind, development engineers need to formulate numerous control strategies. Once the control strategy is evaluated and frozen, it typically does not change from one vehicle model application to another. However, it may happen that Electronic Control Unit (ECU) manufacturer may change depending on the sourcing strategy. Therefore, in order to maintain uniformity, it may be required to compare control strategy of a finished ECU product frozen for one model application to be compared with new ECU sourced through another manufacturer. This paper discusses a methodology to compare control strategy of two ECU’s sourced from different ECU manufacturers with identical control requirements.

In the Indian Context, Fuel Economy of a vehicle is one of key elements while buying a Car. The fuel economy declared by OEMs (Original Equipment Manufacturers) is one of the key indicators while assessing the fuel economy. However it is based on a standard driving cycle and evaluated under standard conditions as mandated by emission legislation. As the driving pattern has a major influence on fuel economy, the objective of this paper is to study real world driving patterns and to define a methodology to simulate a real world driving cycle. A case study was done on Delhi City, by running a fleet of vehicles in different traffic conditions. Thereafter data analysis like acceleration %, specific energy demand per distance, Acceleration vs. Vehicle Speed distribution etc. was done with the help of MATLAB. The final validation of cycle was done by comparing Lab results with on-road Fuel Economy data.

Hardened steel is the majorly used raw material for automotive components. In spite of its abundance, its application is limited due to low fatigue life in dynamic loading. Shot peening is one of the identified processes to improve the fatigue life of the ductile steel by inducing the work hardening & surface improvement. The process of shot peening involves the bombardment of shots on the component surface. As the process & technique, the shot size selection plays very important role in the fatigue life improvement as it alters the results substantially. Also during the process, shot size decreases due to the normal wear of the shots after hitting the component surface. As a result, there is always a ratio of various sizes of the shots involved in the process. Therefore it becomes imperative to control the shot size ratio for obtaining the required work hardening & possible fatigue life improvement.

Interior sound quality is one of the significant factors contributing to the comfort level of the occupants of a passenger car. One of the major reasons for the deterioration of interior sound quality is the booming noise. Booming noise is a low frequency (20Hz∼300Hz) structure borne noise which occurs mainly due to the powertrain excitations or road excitations. Several methods have been developed over time to identify and troubleshoot the causes of booming noise [1]. In this paper an attempt has been made to understand the booming noise by analyzing structural (panels) and acoustic (cavity) modes. Both the structural modes and the acoustic modes of the vehicle cabin were measured experimentally on a B-segment hatchback vehicle using a novel approach and the coupled modes were identified.

Electrostatic charge generation in fabric is a common phenomenon. This phenomenon of charge generation & transfer of the same to human body is more in case of fabrics made of polyester yarns due to interface property of the material. The charge generation may result in attraction of dust on the fabric surface, clinginess & may also result in uncomfortable shock to the human body. This situation is attributed to various parameters such as fabric construction, yarn properties, yarn finish & various coating on the yarn. Since, polyester fabric is prime material used in seating; there have been many incidences of rubbing of seat fabric to human body, resulting in generation of static charge. This study focuses on understanding the effect of various fabric parameters on electrostatic charge generation. The study will also look into various potential solutions to reduce the charge generation with their merits and demerits.

With strict upcoming regulation norms, it becomes a challenging task for automotive industry to develop highly efficient engine that meets all the regulation requirements. The focus of automakers is to utilize fuel energy in most efficient way and to reduce the energy loss from the engine to improve thermal efficiency. Heat loss to the cooling medium is one of the prime losses inside the combustion chamber. Thermal barrier coating is used to reduce heat losses across combustion chamber surfaces (Piston, head, valves and cylinder liner) as it provides good insulation because of the prominent properties of coating materials like low thermal conductivity, low heat capacity, high melting point etc. This paper presents application and impact of thermal swing coating on thermal efficiency. Thermal swing coating material follows gas temperature quickly throughout the cycle which reduces the temperature difference between gas and coating surface and thus reduces the heat loss.

A general automotive car is majorly composed of high strength steel (6%), other steel (50%), Iron (15%), Plastics (7%), Aluminum (4%) and others (Rubber, Glass, Textile) about 18%. End-of-life vehicles (ELVs) are a significant source of waste and pollution in the automotive industry. Recycling ELVs, particularly their plastic components, Li-ion batteries, catalytic converters, and critical technology components such as alternators, semi-conductor chips, and high tensile strength steel can reduce their environmental impact and conserve valuable raw materials. The paper conducts a SWOT analysis and a life cycle assessment (LCA) to evaluate the long-term viability and potential of ELV recycling, environmental impact, and carbon footprint.